Module: RDF::Mutable

Extended by:
Util::Aliasing::LateBound
Includes:
Readable, Writable
Included in:
Changeset, Graph, Repository, Transaction
Defined in:
lib/rdf/mixin/mutable.rb

Overview

Classes that include this module must implement the methods #insert_statement, #delete_statement and #each_statement.

See Also:

Instance Method Summary collapse

Methods included from Util::Aliasing::LateBound

alias_method

Methods included from Writable

#writable?

Methods included from Readable

#readable?

Dynamic Method Handling

This class handles dynamic methods through the method_missing method

# ⇒ String

Implements #from_reader for each available instance of Reader, based on the reader symbol.

Arguments are passed to Reader.new.

Returns:

See Also:

  • RDF::Mutable.{RDF{RDF::Reader{RDF::Reader.sym}


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# File 'lib/rdf/mixin/mutable.rb', line 255

def method_missing(meth, *args)
  reader = RDF::Reader.for(meth.to_s[5..-1].to_sym) if meth.to_s[0,5] == "from_"
  if reader
    self << reader.new(*args)
  else
    super
  end
end

Instance Method Details

#<<(data) ⇒ Mutable

Inserts RDF data into self.

Parameters:

Returns:

Raises:

  • (TypeError) —

    if self is immutable

See Also:



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# File 'lib/rdf/mixin/mutable.rb', line 68

def <<(data)
  raise TypeError.new("#{self} is immutable") if immutable?

  super # RDF::Writable#<<
end

#apply_changeset(changeset) ⇒ Boolean

Applies the given changeset

If ‘#supports?(:atomic_write)` is true, this must apply the changeset atomically. Otherwise, it should offer an efficient implementation of a combined delete/insert of the changeset.

Parameters:

Returns:

  • (Boolean) —

    true if the changeset has been applied



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# File 'lib/rdf/mixin/mutable.rb', line 210

def apply_changeset(changeset)
  delete_insert(changeset.deletes, changeset.inserts)
end

#clear ⇒ Mutable Also known as: clear!

Deletes all RDF statements from self.

Returns:

Raises:

  • (TypeError) —

    if self is immutable



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# File 'lib/rdf/mixin/mutable.rb', line 232

def clear
  raise TypeError.new("#{self} is immutable") if immutable?

  if respond_to?(:clear_statements, true)
    clear_statements
  else
    delete_statements(self)
  end

  return self
end

#delete(*statements) ⇒ self #delete(statements) ⇒ self Also known as: delete!

Note:

using splat argument syntax with excessive arguments provided

Deletes RDF statements from self. If any statement contains a Query::Variable, it is considered to be a pattern, and used to query self to find matching statements to delete.

significantly affects performance. Use Enumerator form for large numbers of statements.

Overloads:

  • #delete(*statements) ⇒ self

    Parameters:

    Returns:

    • (self)

    Raises:

    • (TypeError) —

      if self is immutable

  • #delete(statements) ⇒ self

    Parameters:

    Returns:

    • (self)

    Raises:

    • (TypeError) —

      if self is immutable

Raises:

  • (TypeError) 


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# File 'lib/rdf/mixin/mutable.rb', line 154

def delete(*statements)
  raise TypeError.new("#{self} is immutable") if immutable?

  statements.map! do |value|
    case
      when value.respond_to?(:each_statement)
        delete_statements(value)
        nil
      when (statement = Statement.from(value)).constant?
        statement
      else
        delete_statements(query(value))
        nil
    end
  end
  statements.compact!
  delete_statements(statements) unless statements.empty?

  return self
end

#delete_insert(deletes, inserts) ⇒ Mutable Also known as: delete_insert!

Note:

in the base implementation, this is equivalent to calling #delete and #insert sequentially. This method is preferred to take advantage of (e.g.) RDF::Repositories that can execute the operation in a single request.

Performs a set of deletes and inserts as a combined operation.

Parameters:

Returns:

Raises:

  • (TypeError) —

    if self is immutable

See Also:



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# File 'lib/rdf/mixin/mutable.rb', line 192

def delete_insert(deletes, inserts)
  deletes.respond_to?(:each_statement) ? delete(deletes) : delete(*deletes)
  inserts.respond_to?(:each_statement) ? insert(inserts) : insert(*inserts)

  self
end

#immutable? ⇒ Boolean

Returns true if self is immutable.

Returns:

  • (Boolean)

See Also:



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# File 'lib/rdf/mixin/mutable.rb', line 27

def immutable?
  !mutable?
end

#insert(*statements) ⇒ self #insert(statements) ⇒ self

Note:

using splat argument syntax with excessive arguments provided

Inserts RDF statements into self.

significantly affects performance. Use Enumerator form for large numbers of statements.

Overloads:

  • #insert(*statements) ⇒ self

    Parameters:

    Returns:

    • (self)

    Raises:

    • (TypeError) —

      if self is immutable

  • #insert(statements) ⇒ self

    Parameters:

    Returns:

    • (self)

    Raises:

    • (TypeError) —

      if self is immutable

Raises:

  • (TypeError)

See Also:



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# File 'lib/rdf/mixin/mutable.rb', line 92

def insert(*statements)
  raise TypeError.new("#{self} is immutable") if immutable?

  super # RDF::Writable#insert
end

#load(url, graph_name: nil, **options) ⇒ void Also known as: load!

This method returns an undefined value.

Loads RDF statements from the given file or URL into self.

Parameters:

Options Hash (**options):

  • :graph_name (RDF::Resource) —

    Set set graph name of each loaded statement

Raises:

  • (TypeError) 


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# File 'lib/rdf/mixin/mutable.rb', line 40

def load(url, graph_name: nil, **options)
  raise TypeError.new("#{self} is immutable") if immutable?

  Reader.open(url, {base_uri: url}.merge(options)) do |reader|
    if graph_name
      statements = []
      reader.each_statement do |statement|
        statement.graph_name = graph_name
        statements << statement
      end
      insert_statements(statements)
      statements.size
    else
      insert_statements(reader)
      nil
    end
  end
end

#mutable? ⇒ Boolean

Returns true if self is mutable.

Returns:

  • (Boolean)

See Also:



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# File 'lib/rdf/mixin/mutable.rb', line 18

def mutable?
  writable?
end

#respond_to_missing?(name, include_private = false) ⇒ Boolean

Note:

this instantiates an entire reader; it could probably be done more efficiently by refactoring RDF::Reader and/or RDF::Format to expose a list of valid format symbols.

Returns:

  • (Boolean) 


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# File 'lib/rdf/mixin/mutable.rb', line 268

def respond_to_missing?(name, include_private = false)
  return RDF::Reader.for(name.to_s[5..-1].to_sym) if name.to_s[0,5] == 'from_'
  super 
end

#snapshot ⇒ Dataset

A readable & queryable snapshot of the repository for isolated reads.

This method must be implemented when ‘#supports(:snapshots)` is true.

Returns:

  • (Dataset) —

    an immutable Dataset containing a current snapshot of the Repository contents.

Raises:

  • (NotImplementederror) —

    when snapshots aren’t implemented for the class



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# File 'lib/rdf/mixin/mutable.rb', line 223

def snapshot
  raise NotImplementedError, "#{self.class} does not implement snapshots"
end

#update(*statements) ⇒ self #update(statements) ⇒ self Also known as: update!

Note:

using splat argument syntax with excessive arguments provided

Updates RDF statements in self.

‘#update([subject, predicate, object])` is equivalent to `#delete([subject, predicate, nil])` followed by `#insert([subject, predicate, object])` unless object is nil.

significantly affects performance. Use Enumerator form for large numbers of statements.

Overloads:

  • #update(*statements) ⇒ self

    Parameters:

    Returns:

    • (self)

    Raises:

    • (TypeError) —

      if self is immutable

  • #update(statements) ⇒ self

    Parameters:

    Returns:

    • (self)

    Raises:

    • (TypeError) —

      if self is immutable

Raises:

  • (TypeError) 


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# File 'lib/rdf/mixin/mutable.rb', line 118

def update(*statements)
  raise TypeError.new("#{self} is immutable") if immutable?
  statements = statements[0] if statements.length == 1 && statements[0].is_a?(Enumerable)

  statements.each do |statement|
    if (statement = Statement.from(statement))
      if statement.has_object?
        delete_insert([[statement.subject, statement.predicate, nil]], [statement])
      else
        delete([statement.subject, statement.predicate, nil])
      end
    end
  end
end